1. Field of the Invention
The present invention relates generally to a multilayered heat exchanger consisting of a plurality of alternately layered fins and tube elements and, more particularly, to an improvement in dimensional relationships of the fins and tube elements.
2. Description of the Related Arts
In a heat exchanger having fins and tube elements alternately layered, a heat exchange medium flowing within the tube elements transfers its temperature to the fins, to exchange heat principally by way of the fins with air passing through the spaces defined between the adjacent tube elements. Heat exchangers of the type which have been hitherto manufactured by the present applicant had a fin width FW in the air-flow direction of 74 mm, fin thickness FT of 0.11 mm, fin pitch FP of 3.6 mm, fin height FH of 9.0 mm, and a tube element thickness TW of 2.9 mm. An investigation performed by the present applicant has revealed that for the products by the other manufacturers, the fin width FW in the air-flow direction lies within a range of 64 mm to 110 mm, the fin thickness FT in a range of 0.10 mm to 0.12 mm, the fin pitch FP in a range of 3.4 mm to 4.5 mm, the fin height FH in a range of 8.0 mm to 12.3 mm, and the tube element thickness TW in a range of 2.8 mm to 3.4 mm, which will cover the heat exchanger of the present applicant.
Although it is believed for the heat exchanger that its heat exchange efficiency can be improved by increasing contact areas between the fins and air, if the distances between the adjacent tube elements (or fin height) are increased to enlarge the surface areas of the fins, the heat exchange efficiency will be impaired. Also, if the distances between the adjacent tube elements are reduced to lessen the fin pitch, the air-flow resistance will be increased to impede the flow of air. Nevertheless, while considering not only the improvement in the heat exchange efficiency but also the reduction of the air-flow resistance, the demands to improve the performance of the heat exchanger and reduce the size thereof must be satisfied, which will need a still further improvement of the heat exchanger.